Thoughtful Thursdays: The Role Sharks Play in Maintaining Healthy Ocean Ecosystems

Published August 01, 2013

Sharks, like almost no other animal on this planet, capture our thoughts and imagination – deservedly so. These animals have been around for hundreds of millions of years and have evolved into almost every shape and size. They can be the size of a bus or the size of your smart phone. They can bear live young or lay eggs in open water. They can feed on the smallest plankton or on whale carcasses. They can spend most of their lives on a relatively small section of the sea floor or migrate more than a thousand miles.

Despite their incredible diversity, most species of sharks have several things in common. They generally take a long time to reach reproductive age and have few offspring and although some species can tolerate fresh water, most live in salt water their entire lives. Most are also apex predators and their numbers are declining in ecologically significant ways. A coral reef ecosystem and the incredibly diverse plant and animal community it supports, is directly impacted by the health and abundance of sharks as apex predators – and vice versa.

When we talk about the real and urgent threats sharks are facing - overfishing, shark finning, bycatch and habitat destruction, we are inclined to focus on the issues that are less diffuse, and quite frankly, issues where the blame lies with others. All we have to do is fix the bad habits of others and we can save the world.

While bycatch, overfishing and finning are vitally important to address (70-100 million sharks are killed annually due to these problems alone), we can’t forget that we also need to protect the places - like coral reefs - they depend upon to survive. If we want to ensure the health of our marine species, we’ll need to reverse the widespread destruction of vital coral reef, mangrove, grass bed and wetland habitats. These are nursery or feeding grounds for sharks and other species. Protection of habitat is tightly linked to the well-being of the animals we care so much about.

We are losing these habitats at alarming rates and for a variety of reasons. Climate change and ocean acidification are threatening our coral reefs, coastal development and sea level rise are jeopardizing our important mangrove and wetland areas, and sedimentation and destructive fishing practices are killing our underwater grass beds. If we are going to protect sharks and other ocean species, we’ll need to also focus on these issues. But this time, when we look for the person to blame, we need to accept some personal responsibility. We, as individuals and as a society, are responsible for - and have the power to mitigate for climate change, to make sure development happens in responsible ways, to decrease our collective carbon footprints. We need to hold ourselves responsible for our own individual contributions to this problem and we need to hold each other accountable.

The good news is, as we make strides to restore and protect healthy habitats, the lasting effects cascade throughout the ecosystem – creating supportive environments for healthy plant and animal communities. The better news is we can do something today to make a difference! Volunteer with the National Aquarium or other local conservation organization to restore vital aquatic habitats, choose seafood that has been caught in ways that doesn’t harm sharks, or take a step to reduce your carbon footprint. Sharks deserve our help. Join us!